Vania



(No Model.) 2 sheets-sheet 1.

J. A. STARRETT 8v E. F. WELSH.

LIFTING JACK.

No. 599,536. l. Patented Feb. 22,1898.

Humm...

A 0017.31? MS/v.

. v v "i hmmm (No Model.) 2 Sheets-Sheet 2.

J. A. STARRETT 8v E. F. WELSH.

LIFTING JACK.

No. 599,536. Patented Feb. 22,1898.

ihvrrnn Frarnt JACOB A. STARRETT AND EDWIN F. WELSH, OF VILMERDING,PENNSYL- VANIA, ASSIGNORS OF ONE-TWENTIETII TO IVILLIAM F. IVOOD, OF

SAME PLAGE.

LIFTINGNJCIK.

SPECIFICATION forming part of Letters Patent No. 599,536, dated February22, 1898.

Application tiled October 5, 1897.

T0 @ZZ whom t may concern.-

Be it known that we, JACOB A. STARRETT and EDWIN FVELSH, citizens of theUnited States, residing at Wilmerding, in the county of Allegheny, Stateof Pennsylvania, have invented certain new and useful Improvements inLifting-Jacks, of which the following is a specification, referencebeing had therein to the accompanying drawings.

This invention relates to lifting-jacks, and is particularly adapted forall classes of work in which devices of this character are employed, aswell as for use in connection with oil-well machinery for the purpose ofmanipulating the tools used in such work.

It has for its object to provide a novel means for communicating powerfrom the operatinglever to the lifting-bar and for retaining said bar inits elevated position when the operating-lever is moved to obtain anadditional elevation of the bar.

It has for a further object to provide animproved form of trippingdevice for the purpose of releasing the retaining mechanism when it 'isdesired to lower the liftingebar.

Other objects and advantages of the invention will hereinafter appear inthe following description, and the novel features thereof will beparticularly pointed out in the appended claims.

In the accompanying drawings, Figure l is a vertical section through theinvention.` Fig. 2 is a vertical section on the line 2 2 of Fig. l,looking in the direction of the arrow. Fig. 3 is a detail perspective ofthe tripping device. Fig. 4E is a similar view of the cam-lever. Fig. 5is a detail of the clutch-block, and Fig. 6 is a plan of the liftingmechanism assembled.

Like letters of reference indicate like parts throughout the severalfigures of the drawings. v

The letter A designates a standard provided with a suitable base A andat its upper portion, with parallel segmental extensions A2. The upperportion of the standard is provided j with an enlarged recess A3 for thereception of the lifting, retaining, and tripping mechanism and withinwardly-turned walls ce at its upper portion to guide the lifting-barB, which slides therein. The lower portion of said bar is provided witha foot I3', which is Serial No. 654,156. (No model.)

adapted to engage the article to be lifted, as is usual with this classof devices, and its upper end is provided with ahead B2for a similarpurpose. The bar is smooth throughout its length and iits between thewalls of the standard, so as to slide therein without friction.

For the purpose of lifting the bar an operating-lever O is provided,which is forked at its inner end, as at O', and pivoted to the segmentalextensions A2 by any suitable meansfor instance, a bolt or pintle O2.Journaled upon the inner end. of this lever are oppositelydocated linksD by means ofthe crossbar D2, carried by the forked ends of the lever O.The links are spaced apart and held in their relative positions by meansof a sleeve D2. Embracing the 'lifting-bar is a strap E, formed in twoparts E and secured together by means of a bolt e. The projecting endsof the portions E of the strap are provided with apertures to receivethe pintles F of a cam-lever F, the outer end of said lever beingpivotally connected withl the lower ends of the strap D by means of a journalingpin F2. The cam-lever F is provided with a face or seat portionf, which extends ai an angle to the pivots F', so that when the camleveris rotated it will bear against a clutch-block G, which is locatedbetween the lever and the lifting-bar to hold the lever in position.This block is provided with a roughened or serrated face G and at itsrear with a recess G2, within which the end of the lever operates andagainst the wall of which it bears. By this structure it will be seenthat when the end of the operating-lever is depressed motion willA becommunicated through the links D to the cam-lever F, so that the samewill be thrown into contact with the clutch-block and thus clutch thelifting-bar and lift the same in the upward movement of the .inner endof the operating-lever.

The means for retaining the lifting-bar in its elevated positionconsists of a strap E2, clutchblock G2, and cam-lever F3 similar tothose just described, with the exception that the outer end of thecam-lever is not pivoted to any movable part, but rests upon a stop I-I.Extending downward from the upper portion a of the standard uponopposite sides of the roo lifting-bar are pins H, about which arelocated coil-springs H2, which bear upon the upper surface of the strapE2, and thus normally force the same downward so as to engage the outerend of the cam-lever with the stop H, and thus move the lever so as tobring the clutch-block into contact with the liftingbar. These springsand pins just described may be omitted and any other desirable form ofspring used in their stead. It is obvious that the upward movement ofthe lifting-bar will carry this retaining device slightly upward with itand then pass freely through the same, while the downward `movement ofthe bar will bring the cam-lever into contact with the stop H and thusclutch and hold the bar against further downward movement.

When it is desired to release the retainin gdevice `from the bar inorder to permit the same to be lowered, a tripping-lever is used, suchas is shown in detail in Fig. 3, which consists of a horizontal portionI, j ournaled in the standard and provided at one end with anoperating-handle I. Upon opposite sides of the lifting-bar the trippingdevice is provided with an arm I2, having upwardly-extending pins I3,between which and the lower side of the strap E2 are located springs I4,which are of greater tension or strength than the spring H2, heretoforedescribed. The bar I is pr-ovided with a lug I5, which is adapted toseat itself in a recess I, formed in the standard, when the lug andrecess come into alinement with each other. This lug is normally heldintov contact with the side of the standard by means of a spring I7,located between the head I8 on the tripping device and one wall of thestandard. From this description it will be seen that when the trippingdevice stands in the position shown in Fig. 1 the springs I4 are out ofaction, as their tension is less than the springs H2. If the handle ofthe tripping device be turned at this time, so as to bring the lug I5into the recess I, the springs I4 would be compressed, and being ofgreater tension than the springs II2 when the weight of the lifting-baris released will compress the springs H2, and thus release theclutch-block G, which retains the lifting-bar. This action of the partswill occur when the operating-lever is depressed so as to remove theweight from the retaining device and support it upon the clutch-blockconnected with the lifting-lever. When the weight is so supported, thetripping device will release the retaining-clutch, and the lifting-barmaybe lowered by gradual movement of the operatinglever, which at thistime is clutched to the bar, or, if preferred, by throwing the outer endof the lever upward the bar will be dropped at once to its lowestposition. The operation of the several parts has been fully described,and their relations to one-another in the operation of the lifting-jackas a whole will be clearly understood from the foregoing description.

It is obvious that changes may be made in the specific details ofconstruction of the several parts of the invention without departingfrom the spirit of the same as defined bythe appended claims. Forinstance, the base or lower portion of the lifting-jack may be dispensedwith below the line :n 5c in Fig. l of the drawings and the lifting,retaining, and tripping mechanisms mounted in any suitable manner toadapt them to different classes of work.

Having described our invention and set forth its merits, what we claimas new, and desire to secure by Letters Patent, is-

1. In a lifting-jack, the combination with a lifting-bar and itssupport, an operatinglever, a clutch-block adapted to engage said bar, acam-lever operatin g against said clutchblock, and connections betweensaid cam-lever and operating-lever, of a retaining-strap, a cam-leverpivotally mounted therein and bearing at its power end against astationary member of the support, a clutch-block located between saidcam-lever and lifting-bar, and a spring extending from said strap tosaid support to normally force the strap downward; substantially asspecified.

2. In a lifting-jack, the combination with a lifting-bar and itssupport, of a retainingstrap, a cam-lever pivotally mounted in saidstrap and bearing at the power end against a stationary member of thesupport, a clutchblock located between said cam-lever and lifting-bar,and spring means to normally force said strap downward, substantially asspecied.

3. In a lifting-jack, the combination with a lifting-bar and itssupport, of a retainingstrap, a cam-lever pivotally mounted in saidstrap and bearing at one side against a stationary member of thesupport, a clutch-block located between said cam-lever and liftingbar,and a spring located between the upper end of said strap and the supportfor the bar, substantially as specified.

4. In a lifting-jack, the combination with a lifting-bar and itssupport, of a retainingstrap, a cam-lever pivotally mounted in saidstrap and bearing at one end against a stationary member of the support,a clutch-block located between said cam-lever and liftingbar, a springlocated beneath said strap, and means for increasing and releasing thetension of said spring, substantially as specified.

5. In a lifting-jack, the combination with a lifting-bar and itssupport, of a retainingstrap, a cam-lever pivotally mounted in saidstrap and bearing at one end against a stationary member of the support,a clutch-block located between said cam-lever and liftingbar, a springlocated beneath said strap, and a pivoted arm upon which said spring issupported, substantially as specified.

6. In a lifting-jack, the combination with a lifting-bar and itssupport, of a retainingstrap, a cam-lever pivotally mounted in saidstrap and bearing at one end against a stationary member of the support,a clutch-block IIO located between said cam-lever and liftingbar, aspring located beneath said strap, a pivoted arm upon which said springis supported, and means for retaining said arm in position to hold saidspring under tension,

substantially as specified.

'7. In a lifting-jack, the combination with a lifting-bar and itssupport, of a retainingstrap, a cam-lever pivotally mounted in saidstrap and bearing at one end against a stationary member of the support,acluteh-block located between said cam-lever and liftingbar, a springlocated between the upper end of said strap and the support for the bar,a spring beneath said strap, and means for placing and holding saidspring under tension, substantially as specified.

8. A lifting-jack comprising a lifting-bar, an operating-lever, acam-lever pivotally connected therewith and adapted to elevate said bar,a retaining device adapted to operate in the downward movement of saidbar to retain the same in its elevated position, a tripping a cam-leveradapted to clutch said bar and pivotally connected to theoperating-lever, a retaining-strap, a cam-lever pivoted 'therein toclutch said bar, a stationary support beneath the free end of saidlever, and a spring bearing` upon the upper surface of saidretaining-strap to normally force the same downward, substantially asspecified.

l0.. A lifting-jack comprising a lifting-bar, a support therefor havingoppositely-located extensions, an operating-bar pivoted between saidextensions, a strap surrounding said bar, a cam-lever adapted to clutchlsaid bar and pivotally connected to the operating-lever, aretaining-strap, a cam-lever pivoted therein to clutch said bar, astationary support beneath the free end of said lever, apivotallymounted tripping device adapted to operate beneath saidretaining device to elevate the same and release the clutch upon thebar, and springs interposed between said support and retaining deviceand between said retaining and tripping devices, substantially asspecilied.

In testimony whereof We affix our signatures in presence of twowitnesses.

JACOB A. STARRETT. EDVIN F. VELSH.

Vitnesse-s:

J os. WINGERsoN, GEO. N. BAUERsMrrH.

